Electric contact means



March 10,1959 J. w. GREAMR 2,877,314

ELECTRIC CONTACT MEANS Filed Nov. 10, 1954 25heets-Sheet 1 20a 5;:INVENTOR.

Jay W. Grear, Jr. BY

' Fig. 2

March 10, 1959 J, w, GREAR, JR 2,877,314

ELECTRIC CONTACT MEANS Filed Nov. 10, 1954 2 Sheets-Sheet 2 mlumll, JFHI||| INV EN TOR.

Jay W. Grear, Jr. BY

United States Patent ELECTRIC CONTACT MEANS Jay W. Grear, Jr.,Albuquerque, N. Mex., assignor, by mesne assignments, to the UnitedStates of America as represented by the United States Atomic EnergyCommission Application November 10, 1954, Serial No. 468,171 C 1 Claim.(Cl. 200-87) The present invention relates to means adapted to maintainelectric connections under conditions of vibration or acceleration, andto electric switches embodying such means.

A major difiiculty or disadvantage experienced with electric switchesthat are used in mechanisms subject to vibration, acceleration or shockis a tendency to open and so remain or chatter, i. e., to open and closerapidly. The difficulty is particularly acute with switch mechanisms orrelatively high current rating as the larger terminals and contactingmasses required are more susceptible to vibration, acceleration andshock forces.

The present invention aims to overcome the above and other diflicultiesor disadvantages by providing new and improved means for holdingelectric conducting or contact members in firm interen'g'agement at alltimes and for simultaneously and rapidly absorbing or damping out"applied vibration, acceleration or shock forces.

An object of the present invention is to provide new and improved meansfor maintaining electric switches in closed relationship.

Another object of the invention is to provide improved electric switchmeans of relatively simple, rugged, lightweight, and inexpensiveconstruction.

Another object of the invention is to provide improved chatterminimizing means which may be readily incorporated into electricswitches of small or large sizes and capacities.

Still another object of the invention is to provide yieldable means formaintaining contact elements of a switch in firm interengagement at alltimes.

A still further object of the invention is to provide improved means fordamping out effects of externally applied forces.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

A preferred embodiment of the invention and various modificationsthereof have been chosen for purposes of illustration and description.The preferred embodiment and the modifications are not intended to beexhaustive nor to limit the invention to the precise form disclosed.They are chosen and described in order to best explain the principles ofthe invention and their application in practical use to thereby enableothers skilled in the art to best utilize the invention in variousembodiments and modifications as are best adapted to the particular usecontemplated.

In the accompanying drawings,

Fig. 1 is a fragmentary sectional view showing one form of theinvention;

Fig. 2 is an end view of a slightly different form of the invention;

.Fig. 3 is a side view of the device shown in Fig. 2; and

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Fig. 4 is a fragmentary sectional view of a-modified form of theinvention as it may be employed in a sliding contact mechanism.

As shown in Fig. 1, the invention comprises a pair of spaced apartmembers 1 and 2 carrying terminals 4 adapted to be contacted byelectrically conducting bar members 5 which are secured to guide pins 7.The guide pins 7 extend through apertures in an intermediate or supportmember 10. The spaced members 1 and 2 and the support member 10 may becomposed entirely of any suitable insulating material or include suchinsulating material only adjacent the terminals 4 and guide pins 7. Theintermediate or support member 10 may be normally urged toward oneterminal engaging position bya spring 11 and may be moved toward anopposite contact engaging position by solenoid means 14 which effectsrotation of the support member 10 about an axis or support rod 15. Thecombination of spring 11 and solenoid means 14 with rod 15 for obtainingmovement of the support member 10 is merely illustrative as any othersuitable means may be employed. If desired, the support member 10 may bestationarily mounted and the spaced members 1 and 2 actuated so as toselectively close or open their contacts 4 with respect to one or theother of the conducting members 5 on the support member 10.

An appropriate conducting member 5 (the upper one as shown in Fig. 1) isurged into firm engagement with terminals 4 and applied vibratory,acceleration or other forces are damped out by yieldable means orsprings 18 shown intermediate the conducting members 5 and an adjacentsurface of the support member 10. In Fig. 1 the upper spring 18 isdeflected and presses the conducting bar 5 firmly against the two upperterminals 4 to interconnect them so that a circuit path is establishedthrough the bar 5 from one upper conductor 9 to the other. Leg portions20 of the upper spring are simultaneously urged into firm frictional orsliding engagement with adjacent surfaces of the intermediate supportmember 10. If relative movement, together or apart, between the upperinsulator member 1 and the intermediate support member 10 occurs, theupper spring 18 continues to urge the conducting bar 5 into engagementwith the upper terminals 4 and the projecting leg portions 20 of thespring slide along adjacent surfaces of the support member 10 during themovement. As a result of the sliding or frictional engagement betweenspring legs 20 and support member 10, kinetic energy of the members isquickly absorbed or damped out. In addition to the damping effectprovided by leg portions 20 of the upper spring 18, the damping actionis enhanced by simultaneous frictional or sliding engagement of thelower spring leg portions 20 along the underside of the support member10. The configuration of both springs 20 approximates that shown for thelower spring prior to movement of the support member 10 and consequentdeflection or deformation of the upper spring.

Sliding and frictional engagement of the springs 18 with the supportmember 10 is enhanced by disposing the spring leg portions 20 at anyappropriate angle to the adjacent engaging surface so as to minimize thepossibility of digging thereinto, and also by forming reverse bends onthe legs 20 to provide what may be termed enlarged shoes for engagingand sliding along the support member 10. The enlarged engaging surfacesthus provided between the spring legs 20 and support member 10 morequickly and effectively absorb or damp When the solenoid means 14 isenergized the support member 10 rotates about the axis 15, in oppositionto the spring 11, and the lower conducting member engages with terminals4 of the lower insulator member 2 so as to interconnect the lowerconductors 12 and disconnect the upper conductors 9. When so disposed,the lower spring 18 will be deflected similarly to the illustratedrelationship of the upper spring 20 and the upper spring will then be ofconfiguration similar to that shown in Fig. l for the lower spring.

While the invention as illustrated in Fig. l is adapted to establish acircuit through one set of terminals substantially simultaneously withinterruption of a second circuit through another set of terminals, itwill be clear that one set of terminals and their supporting means maybe omitted and any desired circuit established only in response tomovement of a conducting member 5 in one direction. For example, theupper insulating member 1 with its terminals 4 and the spring 11 may beomitted, so that energization of the solenoid means 14 serves only toconnect the lower conducting member 5 across the terminals 4 of thelower insulating member 2. In such instances the upper spring 18 may, ofcourse, be dispensed with.

The legs 20 of the yieldable means or springs 18 have been disclosed inFig. 1 frictionally engaging and slidable along the support member andwith central portions resting against the conducting members 5. Thesprings may, however, be positioned so that their central portions restagainst a support member and their ends or leg portions slidingly andfrictionally engage conducting bar members, similar to the embodimentshown in Figs. 2 and 3.

In Figs. 2 and 3 the invention is shown embodied in a switch mechanismwhich includes a rotor or support member 10a secured to a rotatableshaft 25 for movement with the shaft in clockwise or counterclockwisedirections, as the case may be, to electrically interconnect oneplurality of sets of terminals 411 and dis connect another plurality ofsets of similar terminals. While the support member 10a, which may becomposed of some insulating synthetic resin or plastic material, isshown with a pair of oppositely disposed wings to facilitate making andbreaking of circuits via the illustrated sets of terminals, only asingle wing may be employed if. desired.

The terminals 4a and associated conducting wires are carried by andproject above a plate member 21 having a hollow hub 22 penetrated by therotatable shaft 25. The shaft 25 and hub 22 may be electrically isolatedfrom each other by an intermediate annular bearing or bushing (notshown) and the rotor or support member 10:: may rest adjacent the end ofthe hub 22 and be secured to the shaft 25 by a washer 26 and nut 27.

The conducting members 5a, as well as the springs 1&1 of the Figs. 2 and3 embodiment, are retained in position on the support member 10a bycooperating upper and lower retaining and guiding members 28, which maybe bolted or otherwise secured to the support member 10a. Inwardlyprojecting end portions 29 of the retaining members 28 extend overadjacent surfaces of the conducting bar members 5a to hold them inopposition to pressure exerted by the energy absorbing springs 1811,which are confined between inner surfaces of the conducting members 5aand oppositely disposed surfaces 30 of the support member 10. Theconducting bars 5a and springs 18a are held against excessive endwisemovement and separation from the, retaining members 28. by cut-outswhich form. shoulder-portionsv 32 and 33, respectively, that projectbeyond adjacent edges of the retaining members 28.

When the actuating shaft 25 is rotatedinone direction the top and bottomconducting bars 5a (Fig. 2) are pressed against their respectiveterminals 4a and the corresponding top and bottom spring members 18a arecompressed from the relationships shown at the right and left sides ofFig. 2 to the deflected positions shown at the top and bottom of Fig. 2.It will be noted that in the embodiment of Figs. 2 and 3 the centralportion of the springs rest against portions of the support rotor member1% and the leg portions 2th: frictionally engage and are slidable alongthe conducting members 511, wherein in the embodiment of Fig. lfrictional engagement and sliding took place along the insulatingmember. In either instance the frictional or sliding engagement quicklyabsorbs or damps out vibratory or acceleration forces and the conductingbars or members 5a are maintained in firm engagement with the terminals4a.

For clarity of illustration the conducting members 5a and springs 18a ofFigs. 1 and 2 are shown disposed at a considerable angle to thecontacting faces of their respective terminals. It will be understoodthat any suitable angles may be utilized; for example, a conductingmember 511 may be positioned so as to engage the faces of a pair ofterminals substantially simultaneously, with the spring exertingsubstantially equal pressure at each of its spaced legs 20a.

Only a single unit is shown on the shaft 25, but any suitable number ofthem may be mounted along the shaft for actuation in response tooperation of a rotary solenoid or other mechanism (not shown).

In some instances it may be desired to utilize the invention in switchmechanisms that are adapted to establish or interrupt circuits by rotarymovement and sliding engagement of a conducting bar. Fig. 4 discloses amechanism of this type. As there shown, a support member 10!; carries aconducting member 5b for selectively establishing contact between acentral terminal 38 and either one of outer terminals 39 or 40 carriedby a support member 41. When the support member 10b is moved to theright, contact is established between central terminal 38 and outerterminal 40 through the contact bar 5b.

The conducting member 5]; is carried by guide pins 7b and is urgedfirmly into contact with ends of the terminals by a spring 18b. Theaction of the spring 18a when the device is subjected to vibratoryshocks, jars or accelerations is similar to that hereinabove describedin connection with Figs. 1 through 3.

The support members lid!) and 41 may be in the form of discs with one ofthem rotatable step by step in response to operation of a rotarysolenoid (not shown).

It will be seen that the present invention provides new and improvedcircuit controlling or switch means adapted to maintain contacts infirmly closed position, even under conditions of extreme vibration,shock or acceleration, and to quickly absorb or dampen kinetic energyforces incident thereto. The device is of relatively simple,lightweight, inexpensive and rugged construction requiring a minimumamount of maintenance or upkeep.

As various changes may be made in the form, construction and arrangementof the parts herein without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in a limiting sense.

What is claimed is:

A support member comprising a base portion and support arms extendingfrom said base in spaced apart relation to provide a guide channel, theends of said support arms being turned towards each other tosubstantially close olf the guide channel, a conducting bridging memberslidably mounted betweensaid support arms and extending transverse on.either side of said guide channel, yieldable means intermediate the rearface of the conducting bridging member andtthe face of the support basenormally urging them apart, the yieldable means having a centralportionbearing against the support base and a plurality of generally radiallyspaced portions each projecting toward and frictionally engaging andslidable along an adjacent surface of the bridging member, support meanscarrying a plurality of spaced electrical terminals, said support meansand support member being relatively movable to selectively place thebridging member in and out of abutting engagement with said terminals.

References Cited in the file of this patent UNITED STATES PATENTS 6Greene a Feb. 14, 1939 Brown Apr. 16, 1940 Judson Dec. 9, 1941 VanValkenburg Feb. 17, 1942 Mason et al Jan. 28, 1947 Cornelius Aug. 12,1947 Du Rocher Nov. 17, 1953 Arnejo Dec. 18, 1956 Spicer et al. Aug. 6,1957 FOREIGN PATENTS Germany Dec. 13, 1925 Germany Oct. 27, 1926

